函数y=(cotx-1)(cos2x-1)
=(cotx-1)[-2(sinx)^2]
=-2cosxsinx+2(sinx)^2
=-sin2x+1-cos2x
=-(根号2)sin(2x+π/4)+1
所以最小正周期T=2π/w=π
递增区间[kπ+π/8,kπ+5π/8],(k是整数)
最大值 根号2,最小值为 -根号2
函数y=(cotx-1)(cos2x-1)
=(cotx-1)[-2(sinx)^2]
=-2cosxsinx+2(sinx)^2
=-sin2x+1-cos2x
=-(根号2)sin(2x+π/4)+1
所以最小正周期T=2π/w=π
递增区间[kπ+π/8,kπ+5π/8],(k是整数)
最大值 根号2,最小值为 -根号2